A computer network is a collection of interconnected computing devices that can exchange data and share resources. The Open Systems Interconnection (“OSI”) model of a network comprises seven layers. A layer two (“L2”) network protocol may, for example, handle framing of data and interface between the higher layers and the physical layer. Ethernet is one example of a L2 communication protocol. Network switches are an example of L2 devices which participate in the exchange of data. Network switches connect a plurality of network devices to each other. A device connected to one port of a network switch is typically able to communicate directly with any other device connected to another port of that network switch.
For example, a network switch operating at the data link layer of the OSI model may forward link-layer frames within an L2 network. That is, the network switch may receive a link-layer frame on a first port of the network switch. If a second port of the network switch is associated with a Media Access Control (MAC) address specified by the link-layer frame, the network switch outputs the link-layer frame on the second port. By outputting link-layer frames in this manner, the network switch of this example may connect two or more link-layer network segments.